Cerebrospinal fluid (CSF) leak after elective lumbar spinal fusion: Who is at risk?

Purpose CSF leaks are a known complication of lumbar fusion surgery. There is a scarcity of literature describing the incidence and risk factors associated with this complication. The aim of this study was to identify patients who are at risk of developing postoperative CSF leak. Methods The Nationwide Inpatient Sample database was used to identify patients who had lumbar fusion in the US from 2002 to 2014. Inpatient outcomes included the incidence and risk of developing CSF leak based on selected patient-specific characteristics. Secondary outcomes included average length of stay, mean costs, and mortality rates. All statistical analyses were conducted based on multivariate regression models using the SPSS software. Results A total of 439,220 patients who underwent elective lumbar fusion procedures were identified. Of these patients, 2.6% (11,636 /439,220) were found to have CSF leak. Independent important risk factors for CSF leak development included: older age (OR: 1.025; 95% CI: 1.02–1.03; p < 0.0001), posterior approach (OR: 1.71; 95% CI: 1.59–1.85; p < 0.0001) compared to anterior approach, chronic deficiency anemia (OR: 1.21; 95% CI:1.14–1.30; p < 0.0001), obesity (OR: 1.22; 95% CI: 1.15–1.30; p < 0.0001), and pulmonary circulatory disease (OR: 1.44; 95% CI: 1.18–1.75; p < 0.0001). CSF leak was associated with increased length of stay (5.39 ± 3.86 vs. 3.74 ± 2.55; p < 0.0001), hospitalization costs (120,129.0 ± 88,123.5 vs. 89,226.8 ± 65,350.3; p < 0.0001) and mortality (0.3% vs. 0.1%; p < 0.05). Conclusion Spine surgeons should be aware of certain patient and procedure-specific characteristics that increase the risk of developing postoperative CSF leak after lumbar fusion in order to improve patient outcomes.